The invention concerns a fluid conducting system for transporting a fluid, in particular air in the intake tract of an internal combustion engine.
Modern internal combustion engines comprise electronic control units in order to provide for optimal engine performance. In this context, for achieving an optimal motor control, a particularly important sensor is a mass air flow meter for influencing the air intake into the internal combustion engine.
For an optimal engine operation, it is decisive that the air volume throughput measurement is precise. A significant problem that affects the air volume measurement are turbulences in the air flow that can cause a great noise signal ratio. In flow controls according to the prior art, it has been attempted to solve this problem by providing devices that reduce the turbulences of the entire flow field.
Usually, the devices according to the prior art utilize either a grid or screen or an aperture. While the devices according to the prior art that are discussed here reduce the turbulences of the entire flow field, they are sensitive to freezing. Moreover, these devices are cost-intensive in regard to manufacture because a high manufacturing precision is required.
Since the measuring cross section surface of the mass air flow meter that is used in this context is significantly smaller than the channel cross section surface that is flowed through by the air flow, a compensation is performed by characteristic maps which in particular also take into consideration a velocity profile within the channel cross section surface. However, it has been found that fresh air filters which may be arranged in the fresh air channel upstream of the measuring device generate a more or less strong change of the velocity profile in the channel cross section depending on their load state. Such a change of the velocity distribution within the channel cross section surface is however not detected by the mass air flow meter so that, with increasing loading of the air filter, the air mass that is determined by the measuring device deviates more and more from the actual air mass flowing through the fresh air channel.
DE 103 43 892 A1 describes an air induction system installed in a motor vehicle. The air induction system comprises an air filter, a clean air channel, an air volume throughput sensor, a mass air flow meter housing channel, and a flow controller. The flow controller is arranged in the center of the mass air flow meter housing channel. The flow controller is arranged upstream of the mass air flow meter and downstream of the air filter in the air flow path. The flow controller has an inlet for entry of air from the clean air channel and an outlet for exit of the air to the mass air flow meter.